Optical and electrical characteristics of GaAs implanted with high energy (70MeV) 120Sn ions

✍ Scribed by AM Narsale; VP Salvi; BM Arora; YP Ali; Uma Bhambhani; Arun Damle; D Kanjilal

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 468 KB
• Volume: 48
• Category: Article
• ISSN: 0042-207X
• DOI: 10.1016/s0042-207x(97)00103-6

✦ Synopsis

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and electrical characteristics of single crystal GaAs substrates implanted with 70 MeV "'Sn ions have been investigated after implantation andsubsequentannealing treatments. The optical density cxx is found to increase with implanted dose overphoton energy range 0.6-1.4 eVand reaches a high saturated value for the samples implanted to a dose of 1 x 1014 ions/cm*. The saturation of ax versus hv suggests amorphisation.

Annealing of higher dose samples above 350°C reduces the density of the radiation defects. The deep lying states seem to be annealing out faster for the annealing temperatures below 450°C while annealing of near band edge damage occurs over the annealing temperature range of 450-600°C. The resistance values of the high dose (I x 1014 ions/cm') samples which is initially low (I 7 kQ), are found to increase with annealing temperatures upto 650°C and then decrease for higher annealing temperatures. The resistance of the samples annealed up to 450°C is dominated by variable range hopping conduction below room temperature.

For the samples annealed at temperatures higher than 45O"C, the electrical transport is dominated by hopping between the neighbouring defect sites. Above 650°C annealing temperatures, the defect states are further reduced and the conduction mechanism is dominated by carriers in the extended states.